/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.mock.web;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.Writer;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.JspWriter;

import org.springframework.lang.Nullable;

/**
 * Mock implementation of the {@link javax.servlet.jsp.JspWriter} class.
 * Only necessary for testing applications when testing custom JSP tags.
 *
 * @author Juergen Hoeller
 * @since 2.5
 */
public class MockJspWriter extends JspWriter {

    private final HttpServletResponse response;

    @Nullable
    private PrintWriter targetWriter;


    /**
     * Create a MockJspWriter for the given response,
     * using the response's default Writer.
     *
     * @param response the servlet response to wrap
     */
    public MockJspWriter(HttpServletResponse response) {
        this(response, null);
    }

    /**
     * Create a MockJspWriter for the given plain Writer.
     *
     * @param targetWriter the target Writer to wrap
     */
    public MockJspWriter(Writer targetWriter) {
        this(null, targetWriter);
    }

    /**
     * Create a MockJspWriter for the given response.
     *
     * @param response     the servlet response to wrap
     * @param targetWriter the target Writer to wrap
     */
    public MockJspWriter(@Nullable HttpServletResponse response, @Nullable Writer targetWriter) {
        super(DEFAULT_BUFFER, true);
        this.response = (response != null ? response : new MockHttpServletResponse());
        if (targetWriter instanceof PrintWriter) {
            this.targetWriter = (PrintWriter) targetWriter;
        } else if (targetWriter != null) {
            this.targetWriter = new PrintWriter(targetWriter);
        }
    }

    /**
     * Lazily initialize the target Writer.
     */
    protected PrintWriter getTargetWriter() throws IOException {
        if (this.targetWriter == null) {
            this.targetWriter = this.response.getWriter();
        }
        return this.targetWriter;
    }


    @Override
    public void clear() throws IOException {
        if (this.response.isCommitted()) {
            throw new IOException("Response already committed");
        }
        this.response.resetBuffer();
    }

    @Override
    public void clearBuffer() throws IOException {
    }

    @Override
    public void flush() throws IOException {
        this.response.flushBuffer();
    }

    @Override
    public void close() throws IOException {
        flush();
    }

    @Override
    public int getRemaining() {
        return Integer.MAX_VALUE;
    }

    @Override
    public void newLine() throws IOException {
        getTargetWriter().println();
    }

    @Override
    public void write(char[] value, int offset, int length) throws IOException {
        getTargetWriter().write(value, offset, length);
    }

    @Override
    public void print(boolean value) throws IOException {
        getTargetWriter().print(value);
    }

    @Override
    public void print(char value) throws IOException {
        getTargetWriter().print(value);
    }

    @Override
    public void print(char[] value) throws IOException {
        getTargetWriter().print(value);
    }

    @Override
    public void print(double value) throws IOException {
        getTargetWriter().print(value);
    }

    @Override
    public void print(float value) throws IOException {
        getTargetWriter().print(value);
    }

    @Override
    public void print(int value) throws IOException {
        getTargetWriter().print(value);
    }

    @Override
    public void print(long value) throws IOException {
        getTargetWriter().print(value);
    }

    @Override
    public void print(Object value) throws IOException {
        getTargetWriter().print(value);
    }

    @Override
    public void print(String value) throws IOException {
        getTargetWriter().print(value);
    }

    @Override
    public void println() throws IOException {
        getTargetWriter().println();
    }

    @Override
    public void println(boolean value) throws IOException {
        getTargetWriter().println(value);
    }

    @Override
    public void println(char value) throws IOException {
        getTargetWriter().println(value);
    }

    @Override
    public void println(char[] value) throws IOException {
        getTargetWriter().println(value);
    }

    @Override
    public void println(double value) throws IOException {
        getTargetWriter().println(value);
    }

    @Override
    public void println(float value) throws IOException {
        getTargetWriter().println(value);
    }

    @Override
    public void println(int value) throws IOException {
        getTargetWriter().println(value);
    }

    @Override
    public void println(long value) throws IOException {
        getTargetWriter().println(value);
    }

    @Override
    public void println(Object value) throws IOException {
        getTargetWriter().println(value);
    }

    @Override
    public void println(String value) throws IOException {
        getTargetWriter().println(value);
    }

}
